Okay, so I have this huge mp3 collection (duh) and I encoded them with several dfiferent encoders over the years. They need to be normalized. I understand that this will inject noise. I understand that some people think I should re-encode from CD my entire collection using a modern encoder, but I'm not going to do that. I'm looking for an automated solution that I can apply to my entire collection and just wait for it to finish. I could use a decoder, normalizer and encoder in sequence, but then I would have to strip the old tag info and tack it back on to the new mp3. Ideally, I would like some software that already does all this and could observe an mp3's peak decoded level, and for example, normalize (to x%) only if the current peak is y% or less, or something like that. Does anyone know of anything like that?

Hmmm.. well you know, you could save a lot of trouble and use RJlov's dynamic compressor with the empeg. They are a lot of threads along this line already. Do a search on Dynamic, or loudness.. hope that helps. There might even be a FAQ entry.

Reg #2845: Mark 1 #00173, Mark 2 #119

Thanks, but thats not the same thing as normalization. I'm not really interested in any compression. I listen to my music loud enough to where I can hear the quiet stuff without additional amplification. Compression is distorting the sound. If it were such good thing, it would already be done for us when we got the CD.

Well, decompressing and recompressing your music will probably annoy you to no end if the compression while in car is a problem for your listening enjoyment.

Most CD's are normalized already anyhow. If you really want to nomalize your entire collection, your better off reripping to prevent quality issues.

Also, from my personal experience, the compressor is really nice. I have it set to only work in the car. I'm glad it's not done to CD's as this would distort things, but I do like having the easy option to do this while in an enviornment where it is useful. You should at least give it a try, as it's easy to install and remove from the empeg.

Okay, so I have this huge mp3 collection (duh) and I encoded them with several dfiferent encoders over the years. They need to be normalized.

As was already mentioned, Richard Lovejoy's Volume Adjustment Kernel is one possible solution. But before you go any further, let's get one thing absolutely clear...

How certain are you that these files really need to be normalized?

You're probably listening to them in shuffle mode, and discovering that they sound like they're all at different volume levels. Is that it?

Well guess what. They're probably already normalized, and the reason they sound like they're all at different volume levels has nothing whatsoever to do with normalization. Most CD's that you buy are already normalized, and they still sound like they're at different volume levels.

It's the same with the difference between TV commercials and TV shows. The commercials are compressed more than the shows, so they sound louder, but both the shows and the commercials are already normalized to the same peak.

Check out the README.TXT in this file for a discussion of the difference between compression and normalization and how they relate to your situation.

In my experience, Richard's kernel helps take the "edge" off of the volume difference between tracks. It doesn't solve the problem 100 percent, but it goes a long way towards it. And the contents of that file will allow you make it selectable and/or adjustable.

Now, if you're certain that your files really need to be normalized, the best way to do it is to re-rip them. You can't decompress/edit/recompress without inducing more compression artifacts.

There is one other option, MP3Trim. This program has the ability to globally increase the volume of an MP3 file without decompressing and recompressing it. A recent version (I didn't know until I checked just now that he'd added it) even allows peak detection for automatic normalizing. Nifty.

But like I said, I'll bet that your stuff is already normalized and this isn't really going to help you. If your music is already normalized, and your complaint is that the volume is different from album to album, the only solution is dynamic compression.

___________
Tony Fabris

I'm not really interested in any compression. I listen to my music loud enough to where I can hear the quiet stuff without additional amplification..

That's OK for you. You drive a Lexus SC-400, one of the quietest cars on the planet with a kick-butt 5-channel amp playing hip-hop and heavy metal tunes totally lacking in quiet parts.1/2 When I'm screaming along in my Carrera at 6000 rpm with the targa top in the boot, picking bugs outta my teeth while playing the second movement of Beethoven's 9th, I could use a little compression!

Compression is distorting the sound. If it were such good thing, it would already be done for us when we got the CD..

Waitamminit! If done right, amplitude compression is non-distortive. I've never built a compressor, but I imagine the trick is to have the time constant longer than half the period of the deepest bass (25 ms, for 20Hz) and shorter than you'd notice a gradual change in volume (several 100 ms). Probably most important is that you can adjust the dBout/dBin ratio to suit your background noise. Ideally you'd just tell it how soft is too soft, and it would compress less when you have it cranked up (soft passages are still audible) and more when you're playing softly (soft passages would be otherwise inaudible). If you had a Carrera you might even want to factor in engine and road speed. The reason they don't compress CDs more than they do, is they don't know how much volume or background noise your going to have.

-jim <MkII:080000260 18G blue>

Compression is distorting the sound. If it were such good thing, it would already be done for us when we got the CD.

Actually, it is done for you on the CD. The problem is that different producers and mastering engineers use different amounts of it, depending on how they want the CD to sound.

A given instrument might have gone through five or more different compressors before it reached your ears. Let's take an electric guitar, for instance. It probably has a pre-effects compressor on the raw signal. Then, within its effects chain, there could be another compressor to even out the sound after the effects have been applied. If the guitarist takes a solo, he probably kicks in a whole other rack of effects just for the lead guitar sound, among which is most likely another compressor. As that guitar track is mixed into the rest of the tracks, it (like many of the other tracks) is probably bounced through another compressor. Then the final mixed tapes are handed off to the mastering facility, which applies another level of compression to the whole mix.

It's that last level, mastering, which determines the perceived volume of a given track. Everyone does it a little bit differently. A discussion of this process can be found here:

http://www.digido.com/compression.html

Waitamminit! If done right, amplitude compression is non-distortive. I've never built a compressor, but I imagine the trick is to have the time constant longer than half the period of the deepest bass (25 ms, for 20Hz) and shorter than you'd notice a gradual change in volume (several 100 ms).

Actually, in a real compressor, there are several adjustable parameters, including attack time and release time.

And although you can make the argument that compression is "non-distortive", it depends on your definition of distortion. A compressor alters the dynamics of a sound signal, and in many cases, changes its character. If you consider "alteration of the original signal" to be distortion, then yes, by definition, a compressor distorts the signal.

The trick is to do it in a nice way that achieves your goal without compromising the "flavor" of the original audio signal. But it depends on what your goal is. As a guitarist, sometimes I want the compressor on my lead guitar to significantly alter the character of the notes I'm playing. If you just want all your albums to sound like they're at the same volume, then more subtle compressor adjustments are necessary, and you have to decide where you want the trade-offs.

___________
Tony Fabris

Well guess what. They're probably already normalized, and the reason they sound like they're all at different volume levels has nothing whatsoever to do with normalization. Most CD's that you buy are already normalized, and they still sound like they're at different volume levels..

The entire CD is scaled so that the loudest instant of the loudest track is just shy of clipping. That means if you're listening to the Brandenburg Concerto with cannon fire, the bulk of the music will be far below the peak. On the other hand, if you're listening to a CD full of harpsichord solos, the bulk of the music is just about as loud as the peak. Therefore if you switch from one track to the other, the harpsichord track will sound much louder (not what you want).

So how do you keep eight strings of a harpsichord from being as loud as a twenty-one gun salute? Well compressing amplitude will help somewhat, but as sc400 said, that's not ideal. What you need is a line in the info file (ending with a 1) associated with each mp3 file (ending with a 0) that gives a volume offset in dB. This would make song sound XdB softer than what you currently have the volume set to. If you individually renormalize each track on a CD you would want to compensate the offset number accordingly so when played, every track had the same relative volume as the recording engineer intended. That way you would maximize the noise performance of the crappy DACs on the Philips DSP (next time use Analog Devices) and place more burden on the variable gain Burr-Brown amps (almost as good as Analog Devices). All quiet tracks would sound better! You could set the offset before renormalization by ear (once for every CD), but that would be a huge pain in the @ss for a big collection. I doubt you could even do it consistently unless you were very careful. A much easier way would be to run a rms detector across every album and set the offsets for that album so that every album was, on average the same loudness. Then sc400 can sit in his quiet Lexus with his empeg on full random, and rarely adjust the volume levels. If "rarely" wasn't good enough you could manually adjust the offset levels for albums that you want to be quiet.

-jim <MkII:080000260 18G blue>

What you need is a line in the info file (ending with a 1) associated with each mp3 file (ending with a 0) that gives a volume offset in dB.

This has already been suggested (once upon a time, I think I may have been the one suggesting it), but this also wouldn't work for the intended purpose. In order for the cannon-fire piece to sound as loud as the harpsichord piece, you would need to either a) increase the cannon-fire piece so loud as to severely distort when the cannons went off, or b) decrease the volume of the harpsichord piece so far that you lose all detail when listening to it.

There are all sorts of implementation issues making such a system difficult, too.

If you're complaining about dynamic differences and are not willing to listen to all of the songs at their original recorded volumes, then your only solution is dynamic range compression.

___________
Tony Fabris

Thanks for the education and nice link! I was hoping someone would chime in with some real-world experience. I'm sure you musicians explore the full spectrum of compression from instantaneous non-linear mapping to subtle AGC that evens out undesired volume changes over the time frame of an entire track.

Most of us listeners have much more modest goals. We want to get a comfortable volume level *without* changing the flavor. All sc400 is asking for is to make a single gain adjustment for each track. For those of us with worse stereos or louder cars, we have to cut a more delicate balance between preserving the original feel of the music and drowning out softer passages.

-jim <MkII:080000260 18G blue>

If you're complaining about dynamic differences and are not willing to listen to all of the songs at their original recorded volumes, then your only solution is dynamic range compression..

After all the wonderful posts I've read of yours, I'm surprised to disagree with you here. Perhaps I'm missing something. Let me spout a few generalities and please gently correct me if I say something outlandish:

1) If your stereo doesn't have more dynamic range than your ears, you might like a better stereo.

2) CDs (and I believe the DAC on the empeg's Philips DSP) use 16-bit quantization.

3) We *can* hear better than 16-bits.

4) We *can* build better than 16-bits. (There are really nice 24-bit sigma-delta DACs out there that can sample at least 8x faster than CD's encode rate.)

5) To deal with the limitations of a CD, recording engineers tend to normalize to the loudest passage on the CD, so that the quietest passage in the CD is as high as possible above the noise floor.

6) To deal with 5), listeners tend to enjoy different CDs using different volume settings. (We turn down the harpsichord so that it's softer than the cannon fire, even if they're on two CDs at the same levels).

7) Considering music collection in it's entirety, I'd say the recording engineers have collectively compressed our music collection so that each CD can sound its best, without regard to the volume you might want to play it. (As they should).

8) When sc400 drives me to lunch, he cranks up head-banging tracks and turns down sentimental ballads.

It sounds to me like number 7) is similar to very slow compression. It sounds to me like 8) is similar to very slow expansion. I don't think that further compression is what sc400 is looking for. In contrast, during open top motoring in a Carrera, the difference between deafening and drowned out is less than 16-bits. For me compression is desireable, if done well.

In either case, one compresses just before passing through a channel that is limited in dynamic range. Once past the compromised channel, inverse operations are in order. If the compromised channel is the air, you have to wait until someone invents a pshyco-acoustical expansion implant for your brain.


-jim <MkII:080000260 18G blue>

Wow, great bunch of posts while I was on vacation! I'll need some time to asymilate all that. It sounds like I should at minimum give RJlov's patch a try and see if I still have similar complaints or no complaints or all new complaints. Thanks again guys.

Wouldn't that be funny if you *did* like compression after I argued all the reasons why you wouldn't. Not the first time I made a horse's @ss outta myself. I'm glad I don't have a .jpg of myself attached to every post. Well, I always say, "Never stop just short of making a complete fool of yourself". So I did a little reasearch.

A guy at work has about 17G of mp3 on our Sun network. While I'm not saying I'm nuts about his selections, I think it represents a pretty broad variety of genres. Even a stupid f@rt like me can write C for command line use, so I wrote a tiny program to measure the RMS and PEAK levels of a data stream from stdin. A few lines of sed, xargs and a 10 hours of an dual processor Sparc later, decoded them into streams, concatenated by album then piped to my little program. Below are the results. As I opined earlier, the recording engineers cranked up the signal until the loudest passage of the entire album hit full scale or darn close to it. The average volume is therefore much louder if the peak to RMS ratio is small. Green day's average volume is 7dB below fullscale (I find that hard to believe, maybe I should double check my script), while anything classical is more than 20dB below fullscale. Even if you are unlikely to have Green Day and Tchaikovsky shuffled in the same playlist, it would be a little annoying if you were blasting Jethro Tull to the limit of deafness and then you empeg served up a Santana track that averaged a full 8.5 dB louder.

I have my own modest proposal (maybe the same as Tony's?), but I'm tired, so it will have to wait for tomorrow.

RMS PEAK group-album
-07.0dB 0.0dB green_day_nimrod
-08.1dB 0.0dB edwin_mccain_messenger
-08.2dB 0.0dB marc_anthony-marc_anthony
-08.3dB 0.0dB journey_greatest_hits_live
-08.5dB 0.0dB cowboy_mouth-mercyland
-08.5dB 0.0dB garbage-version2.0
-08.5dB 0.0dB vertical_horizon_everything_you_want
-08.6dB 0.0dB metallica-load
-08.6dB 0.0dB ultimate_dance_party
-08.7dB 0.0dB foo_fighters-the_colour_and_the_shape
-08.7dB 0.0dB macy_gray-on_how_life_is
-08.8dB 0.0dB jock_jams_1
-08.9dB 0.0dB santana-supernatural
-09.0dB 0.0dB tribe_called_quest_anthology
-09.1dB 0.0dB mos_def-black_on_both_sides
-09.2dB 0.0dB rage_against_the_machine_battle_of_los_angeles
-09.3dB 0.0dB jock_jams_2
-09.4dB 0.0dB megadeth-cryptic_writings
-09.4dB 0.0dB steve_perry_greatest_hits+five_unreleased
-09.5dB 0.0dB mtv_party_to_go_6
-09.6dB 0.0dB godsmack
-09.6dB 0.0dB shawn_colvin_a_few_small_repairs
-09.7dB 0.0dB swing_this_baby
-09.8dB 0.0dB indigo_girls_come_on_now_social
-10.1dB 0.0dB faith_no_more-angel_dust
-10.1dB 0.0dB joe_diffie-a_night_to_remember
-10.2dB 0.0dB sons_of_the_desert-change
-10.3dB 0.0dB john_lee_hooker_the_best_of_friends
-10.4dB 0.0dB dave_matthews_band-beyond
-10.4dB 0.0dB mtv_party_to_go_8
-10.4dB 0.0dB sinead_oconnor-gospel_oak
-10.6dB 0.0dB beastie_boys_hello_nasty
-10.6dB 0.0dB tool-aenima
-10.8dB 0.0dB harvey_danger-where_have_all_the_merrymakers_gone
-10.8dB 0.0dB mary_chapin_carpenter_party_doll_and_other_favorites
-10.8dB 0.0dB will_smith_big_willie_style
-11.0dB 0.0dB jake_trout_and_the_flounders_i_like_to_play
-11.0dB 0.0dB seal
-11.0dB 0.0dB tangerine_dream-tyranny_of_beauty
-11.1dB 0.0dB stone_temple_pilots-core
-11.2dB 0.0dB ally_mcbeal
-11.2dB 0.0dB beastie_boys_check_your_head
-11.2dB 0.0dB cowboy_mouth-word_of_mouth
-11.2dB 0.0dB eagles_hell_freezes_over
-11.2dB 0.0dB ll_cool_j_all_world
-11.3dB 0.0dB beastie_boys_ill_communication
-11.3dB 0.0dB dave_matthews_band_live_at_red_rocks_2
-11.3dB 0.0dB manhattan_transfer_swing
-11.3dB 0.0dB mtv_party_to_go_2
-11.3dB 0.0dB roomful_of_blues_under_one_roof
-11.6dB 0.0dB dave_matthews_band_live_at_red_rocks_1
-11.8dB 0.0dB david_wilcox-turning_point
-11.9dB 0.0dB boyz_ii_men_ii
-11.9dB 0.0dB tangerine_dream-le_parc
-11.9dB -0.2dB jimi_hendrix_woodstock
-12.0dB 0.0dB frank_sinatra_and_the_tommy_dorsey_orchestra_love_songs
-12.0dB 0.0dB sarah_mclachlan-mirrorball_disc_1
-12.0dB 0.0dB tangerine_dream-underwater_sunlight
-12.1dB 0.0dB jewel_spirit
-12.2dB 0.0dB dance_mix_usa
-12.2dB 0.0dB indigo_girls_shaming_of_the_sun
-12.2dB 0.0dB lilith_fair_1
-12.2dB 0.0dB metallica
-12.3dB 0.0dB johnny_lang_lie_to_me
-12.3dB 0.0dB reo_speedwagon-the_ballads
-12.4dB 0.0dB boston
-12.4dB 0.0dB lilith_fair_2
-12.6dB 0.0dB david_arkenstone_return_of_the_guardians
-12.6dB 0.0dB david_wilcox-big_horizon
-12.6dB 0.0dB sarah_mclachlan-mirrorball_bonus_cd
-12.7dB 0.0dB dixie_chicks_fly
-12.9dB 0.0dB pat_boone_in_a_metal_mood
-12.9dB 0.0dB phil_collins-hits
-12.9dB 0.0dB sling_blade_soundtrack
-12.9dB 0.0dB susan_tedeschi_just_wont_burn
-13.1dB 0.0dB vertical_horizon_live_stages
-13.3dB 0.0dB beatles_anthology_2
-13.3dB 0.0dB lyle_lovett_live_in_texas
-13.3dB 0.0dB mtv_party_to_go_3
-13.3dB 0.0dB robyn_hitchcock_moss_elixir
-13.3dB 0.0dB the_chi-lites
-13.5dB 0.0dB dar_williams_mortal_city
-13.5dB 0.0dB indigo_girls_rites_of_passage
-13.5dB 0.0dB shut_up_and_dance
-13.6dB 0.0dB george_strait_strait_out_of_the_box_3
-13.6dB 0.0dB marvin_gaye-the_master_disc_3
-13.6dB 0.0dB spin_doctors-pocket_full_of_kryptonite
-13.7dB 0.0dB coltrane_live_at_birdland
-13.8dB 0.0dB emerson_lake_and_palmer_best_of
-13.8dB 0.0dB george_strait_strait_out_of_the_box_2
-13.8dB 0.0dB jimi_hendrix_the_ultimate_experience
-13.9dB 0.0dB barenaked_ladies-maybe_you_should_drive
-13.9dB 0.0dB george_benson_the_best_of_benson
-13.9dB 0.0dB get_shorty_soundtrack
-13.9dB 0.0dB marvin_gaye-the_master_disc_4
-13.9dB 0.0dB the_commitments_vol_2
-14.1dB 0.0dB george_strait_strait_out_of_the_box_1
-14.1dB 0.0dB various-superhits_of_the_70s
-14.3dB 0.0dB bb_king_blues_summit
-14.3dB 0.0dB jars_of_clay
-14.3dB -0.0dB beatles_let_it_be
-14.3dB -0.1dB beatles_revolver
-14.4dB 0.0dB boyz_ii_men_cooleyhighharmony
-14.4dB 0.0dB shawn_colvin_cover_girl
-14.5dB 0.0dB spyro_gyra_morning_dance
-14.5dB -0.0dB cure-wish
-14.5dB -0.3dB gipsy_kings
-14.6dB 0.0dB muddy_waters_his_best_1956_to_1964
-14.7dB 0.0dB george_strait_strait_out_of_the_box_4
-14.7dB 0.0dB stevie_ray_vaughan_texas_flood
-14.8dB 0.0dB andrea_bocelli_romanza
-14.8dB 0.0dB bjork_debut
-14.8dB 0.0dB blue_note_story_of_modern_jazz_1
-14.8dB 0.0dB jimmy_buffett_bars
-14.8dB 0.0dB mtv_party_to_go_4
-14.8dB 0.0dB nando_lauria_novo_brasil
-14.8dB 0.0dB sarah_mclachlan_the_freedom_sessions
-14.8dB 0.0dB tori_amos-under_the_pink
-14.9dB 0.0dB greatest_disco_groups
-15.0dB 0.0dB barenaked_ladies-gordon
-15.0dB 0.0dB blue_note_story_of_modern_jazz_2
-15.0dB 0.0dB kate_bush-the_red_shoes
-15.0dB 0.0dB ray_charles_birth_of_soul_2
-15.0dB 0.0dB shawn_colvin-fat_city
-15.1dB 0.0dB anything_goes_the_cole_porter_songbook
-15.1dB 0.0dB don_henley_end_of_the_innocence
-15.2dB 0.0dB jazzmasters_volume_4_disc_4
-15.2dB 0.0dB kate_bush-hounds_of_love
-15.2dB 0.0dB nat_king_cole_unforgettable
-15.2dB -0.0dB 60s_hits_volume_one
-15.3dB 0.0dB george_winston_plains
-15.3dB 0.0dB ll_cool_j-mama_said_knock_you_out
-15.3dB 0.0dB ray_charles_greatest_hits_disc_2
-15.3dB 0.0dB the_generals_daughter_soundtrack
-15.3dB 0.0dB tori_amos-boys_for_pele
-15.3dB -0.0dB moody_blues_best_of
-15.4dB 0.0dB david_wilcox-east_asheville_hardware
-15.4dB 0.0dB john_coltrane_black_pearls
-15.4dB -0.0dB kate_bush-the_dreaming
-15.5dB 0.0dB karen_carpenter
-15.5dB 0.0dB reservoir_dogs_soundtrack
-15.6dB 0.0dB david_wilcox-nightshift_watchman
-15.6dB 0.0dB otis_redding_the_very_best_of
-15.6dB 0.0dB ray_charles_birth_of_soul_1
-15.6dB 0.0dB stan_getz_bossa_nova
-15.6dB 0.0dB us3
-15.7dB 0.0dB ella_fitzgerald_the_best_of_the_song_books_the_ballads
-15.7dB 0.0dB jazzmasters_volume_4_disc_5
-15.7dB 0.0dB righteous_brothers_very_best_of
-15.8dB 0.0dB arrested_development_3_years_5_months
-15.8dB 0.0dB jim_brickman_picture_this
-15.8dB 0.0dB vertical_horizon_running_on_ice
-15.8dB -0.0dB faith_no_more-the_real_thing
-15.8dB -0.1dB pink_floyd-the_dark_side_of_the_moon
-15.8dB -0.4dB stan_getz_and_the_oscar_peterson_trio
-15.8dB -0.6dB beatles_sgt_peppers_lonely_hearts_club_band
-15.9dB 0.0dB fugees-the_score
-15.9dB 0.0dB jazzmasters_volume_4_disc_3
-15.9dB 0.0dB jimmy_buffett_beaches
-15.9dB 0.0dB tis_the_season_celtic_christmas
-16.0dB -1.0dB jimmy_buffett_havana_daydreamin
-16.1dB 0.0dB jazzmasters_volume_4_disc_2
-16.1dB 0.0dB sly_and_the_family_stone-greatest_hits
-16.1dB -0.3dB ella_fitzgerald_the_best_of_the_song_books
-16.2dB 0.0dB david_wilcox-underneath
-16.2dB 0.0dB ella_fitzgerald_best_of_the_songbooks_love_songs
-16.2dB -0.0dB beatles_rubber_soul
-16.3dB 0.0dB abba-gold_greatest_hits
-16.3dB 0.0dB allman_brothers_dreams_1
-16.3dB 0.0dB club_mtv
-16.3dB 0.0dB readers_digest_easy_listening_jazz_classics_3
-16.3dB -0.1dB david_osborne_keys_to_the_heart
-16.4dB 0.0dB christmas_spirit
-16.4dB 0.0dB vonda_shepherd-its_good_eve
-16.4dB -0.2dB david_arkenstone_spirit_wind
-16.4dB -0.2dB roger_miller_king_of_the_road
-16.4dB -0.8dB neil_diamond_his_12_greatest_hits
-16.5dB -0.0dB bb_king_paying_the_cost_to_be_the_boss
-16.6dB 0.0dB ella_fitzgerald_ella_in_rome
-16.6dB -0.8dB al_green_im_still_in_love_with_you
-16.7dB 0.0dB allman_brothers_dreams_3
-16.7dB 0.0dB benny_goodman_essential
-16.7dB 0.0dB david_wilcox-home_again
-16.7dB 0.0dB jane_siberry_bound_by_the_beauty
-16.7dB 0.0dB john_lee_hooker_dont_look_back
-16.7dB 0.0dB ll_cool_j-radio
-16.7dB -0.0dB benny_goodman_yale_archives_volume_5_disc_1
-16.8dB 0.0dB jimmy_buffett_ballads
-16.9dB 0.0dB bonnie_raitt_luck_of_the_draw
-16.9dB -0.3dB kate_bush-the_sensual_world
-16.9dB -1.2dB stan_getz_luiz_bonfa_jazz_samba_encore
-17.0dB 0.0dB allman_brothers_dreams_2
-17.0dB 0.0dB jazzmasters_volume_4_disc_1
-17.0dB 0.0dB jimmy_buffett_changes_in_latitudes_changes_in_attitudes
-17.0dB 0.0dB miles_davis-love_songs
-17.0dB -0.1dB beastie_boys-pauls_boutique
-17.0dB -1.4dB christmas_carols_for_children
-17.1dB 0.0dB elton_john-greatest_hits_volume_ii
-17.1dB 0.0dB michelle_shocked-mercury_poise
-17.1dB -0.2dB tom_waits_closing_time
-17.1dB -0.3dB bread_anthology
-17.1dB -1.0dB america-history_america's_greatest_hits
-17.3dB 0.0dB allman_brothers_dreams_4
-17.3dB -0.4dB jimi_hendrix_experience-live_at_winterland
-17.3dB -1.2dB aretha_franklin_greatest_hits_1980_to_1994
-17.4dB 0.0dB jethro_tull_original_masters
-17.4dB 0.0dB muddy_waters_the_chess_box_3_1960_to_1972
-17.4dB 0.0dB sinead_oconnor-am_i_not_your_girl
-17.4dB -0.0dB bonnie_raitt_nick_of_time
-17.4dB -0.1dB david_wilcox-how_did_you_find_me_here
-17.4dB -0.7dB john_cougar_american_fool
-17.6dB 0.0dB beastie_boys_license_to_ill
-17.6dB 0.0dB danny_wright_christmas_by_candlelight
-17.6dB -0.0dB london_philharmonic-us_and_them-symphonic_pink_floyd
-17.7dB -0.2dB mary_chapin_carpenter_stones_in_the_road
-17.9dB 0.0dB david_osborne_upon_a_midnight_clear
-17.9dB -0.0dB benny_goodman_yale_archives_volume_5_disc_2
-17.9dB -0.3dB joplin_greatest_hits
-18.0dB 0.0dB tom_waits_franks_wild_years
-18.1dB -0.1dB dr_hook_greatest_hits
-18.2dB 0.0dB frank_sinatra_gold
-18.2dB 0.0dB sweet_honey_in_the_rock_i_got_shoes
-18.2dB -0.5dB george_jones_super_hits
-18.2dB -0.8dB david_osborne_introducing_david_osborne
-18.3dB 0.0dB greatest_of_the_guess_who
-18.3dB -0.0dB tom_waits_rain_dogs
-18.4dB 0.0dB tracy_chapman
-18.4dB -0.1dB wynton_marsalis_volume_3_standard_time
-18.5dB 0.0dB wynton_marsalis_crescent_city_christmas_card
-18.5dB -2.2dB styx_the_grand_illusion
-18.6dB 0.0dB simon_and_garfunkel_concert_in_central_park
-18.6dB 0.0dB this_is_jazz_32_billie_holiday
-18.7dB -0.4dB benny_goodman_yale_archives_volume_1
-18.9dB -1.8dB danny_wright_black_and_white_seven
-19.1dB -2.1dB david_osborne_especially_for_you
-19.2dB 0.0dB lyle_lovett_i_love_everybody
-19.3dB -0.6dB cowboy_junkies_the_trinity_sessions
-19.3dB -1.6dB herb_albert_and_the_tijuana_brass_christmas_album
-19.4dB -1.4dB elton_john_greatest_hits
-19.5dB 0.0dB tom_waits_swordfishtrombones
-19.5dB -1.2dB vince_guaraldi_trio_charlie_brown_christmas
-19.7dB -0.4dB sinead_oconnor_i_do_not_want_what_i_havent_got
-19.8dB -0.0dB emile_pandolfi_an_affair_to_remember
-20.2dB -0.3dB bert_and_i
-20.3dB -0.0dB 100_classical_masterpieces_vol_2
-20.3dB -0.3dB benny_goodman_yale_archives_volume_2
-20.4dB 0.0dB emile_pandolfi_evening_in_venice
-21.0dB -0.1dB david_osborne_my_heart_will_go_on
-21.2dB -1.0dB 100_classical_masterpieces_vol_3
-21.3dB -0.2dB 100_classical_masterpieces_vol_1
-21.3dB -0.2dB david_osborne_music_of_the_night
-21.4dB -1.1dB 100_classical_masterpieces_vol_4
-21.4dB -1.8dB erroll_garner_yesterdays_the_savoy_sessions
-21.7dB -1.2dB old_and_in_the_way
-21.8dB -0.2dB david_osborne_just_as_i_am
-22.2dB -0.4dB frederic_chopin-14_waltzes_and_4_impromptus
-22.2dB -0.7dB manheim_steamroller_christmas
-22.3dB -0.9dB 100_classical_masterpieces_vol_5
-22.8dB -0.2dB tchaikovsky_swan_lake

-jim 080000260 w/18G in a Carrera

FASCINATING.

This is the first analysis I've seen of the RMS levels of various songs from different genres. Cool.

As you and I both said, this shows that the vast majority of CDs are already fully normalized. And as was already said, normalization has nothing to do with perceived volume, just because two songs hit the same peak doesn't mean their RMS levels are the same.

I have only one skepticism about the list you just posted, which is: I don't think that RMS measurement is a good judge for perceived volume, either. That doesn't make the list any less interesting, but if you're thinking that you could adjust the volume of a given group of tracks based on those numbers, I'd be surprised if it sounded like what you expected it to.

___________
Tony Fabris

It sounds like I should at minimum give RJlov's patch a try

For what it's worth, here are my experiences with rjlov's Voladj kernal.

It did just what it was supposed to do -- make the quiet parts louder and the loud parts quieter. If this is your only goal, you will probably be happy. However (you knew there was a however coming, didn't you?) the price I had to pay for that on-the-fly normalization was more than I was willing to pay.

On very quiet passages, the three-second ramp-up of volume was disconcerting, and if it was an older recording, along with the increase in volume came an increase in floor noise, i.e., "tape hiss" or equivalent.

I bought the 1812 Overture CD discussed here and to my surprise voladj completely neutered the cannon fire, as it did to the mirror-shaking bass hits in Crystal Method's "Busy Child" on the Vegas album.

While Voladj did bring up detail in bass and mid-bass that I hadn't heard before, it also "smoothed" over the dynamics of mid-bass and treble to such an extant that clarity and brightness were greatly compromised, and "punchiness" of attacks was made much more mellow.

I couldn't live with the loss of dynamic range. I listen mostly (95%) to classical music, and doggone it, some passages are just supposed to be softer than others! Ravel's Bolero becomes elevator music when the whole piece is played at the same dynamic level.

Please don't think I am impugning Richard's work with his Voladj kernal. It is a tremendous accomplishment. But if, like me, you value the sound of a piece of music as much as (or more than) the music itself (how else would you explain my having Crystal Method and Tchaikovsky in the same playlist? ) then chances are that Voladj or any other compression scheme will not be to your complete satisfaction.

But, do try it and see if you like it. Far be it from me to tell you what your music should sound like. Except... that's kind of what I've been doing for the last five paragraphs or so, isn't it?

tanstaafl.



"There Ain't No Such Thing As A Free Lunch"

Of course, as we've already discussed in private e-mails, all of the things you listed are the whole point of dynamic range compression. Depending on the way you look at it, and depending on what your goals are, these things can be viewed as either "unwanted side effects", or "benefits".

The ability to turn it on and off, as well as the ability to adjust its parameters, is why I like the "ioctl" software. Certain kinds of music would tend to benefit more from compression than others. I'll bet that if we could take the time to sit down and play with the parameters, we could come up with some settings that would make you happier. The default settings are a little harsh and could be mellowed out a bit.

___________
Tony Fabris